A connection line of this type can be used in motor vehicles which are driven by an electric motor, particularly advantageously in motor vehicles which have an internal combustion engine and an electric motor. A corresponding motor vehicle is known as a “hybrid car” and is also called such in the text which follows. A hybrid car is equipped with two different motors: an internal combustion engine (petrol or diesel) and an electric motor. It is possible to optionally change over from one motor to the other using known technology. When the hybrid car is operated using the electric motor, no exhaust gases are produced. This is particularly advantageous for city driving. The electric motor is fed from a correspondingly dimensioned power source. It can also be operated such that it generates additional power when the internal combustion engine is still operating, so that both motors then act as drives for the hybrid car. This option may be advantageous particularly when driving uphill and also when overtaking.
In known technology, the electric motor is a three-phase motor for whose operation an alternating current is generated by an inverter which is likewise accommodated in the hybrid car and is connected to a power source. The power source is, for example, an energy-storage means which comprises a large number of capacitors (ultracaps) and can be accommodated, for example, in the boot of a hybrid car. The capacitance of the capacitors is sufficient for brief operation of the electric motor. They are recharged, for example during braking of the motor vehicle, by the electric motor which then acts as a generator. In order to operate, the electric motor is connected to the inverter by means of an electrical connection line, and the inverter, for its part, is connected to the energy-storage means via an electrical connection line. Accordingly, “units” are, in particular, the electric motor, the inverter and the energy-storage means. Fail-safe connection lines are required for the electrical connections of the units.
EP-A-0 901 193 discloses an electrical connection line with a coupling element which is fitted to one end of the said electrical connection line in a moisture-tight manner. This connection line is designed as a three-phase line with three insulated electrical conductors which are surrounded by an electrical outer sheath which is closed all the way around.